Abstract
In the last 15 years, zeolite-like mayenite, Ca12 Al14 O33, has attracted significant attention in material science for its variety of potential applications and for its simple composition. Hydrogen plays a key role in processes of electride material synthesis from pristine mayenite: {Ca12 Al14 O32 }2+ (O2 ) → {Ca12 Al14 O32 }2+ (e− )2 . A presence of molecular hydrogen in synthetic mayenite was not confirmed by the direct methods. Spectroscopy investigations of mayenite group mineral fluorkyuygenite, with empirical formula (Ca12.09 Na0.03 )∑12.12(Al13.67 Si0.12 Fe3+ 0.07Ti4+ 0.01)∑12.87O31.96 [F2.02 Cl0.02 (H2 O)3.22 (H2 S)0.15 □0.59 ]∑6.00, show the presence of an unusual band at 4038 cm−1, registered for the first time and related to molecular hydrogen, apart from usual bands responding to vibrations of mayenite framework. The band at 4038 cm−1 corresponding to stretching vibrations of H2 is at lower frequencies in comparison with positions of analogous bands of gaseous H2 (4156 cm−1 ) and H2 adsorbed at active cation sites of zeolites (4050–4100 cm−1 ). This points out relatively strong linking of molecular hydrogen with the fluorkyuygenite framework. An appearance of H2 in the fluorkyuyginite with ideal formula Ca12 Al14 O32 [(H2 O)4 F2 ], which formed after fluormayenite, Ca12 Al14 O32 [□4 F2 ], is connected with its genesis. Fluorkyuygenite was detected in gehlenite fragments within brecciaed pyrometamorphic rock (Hatrurim Basin, Negev Desert, Israel), which contains reduced mineral assemblage of the Fe-P-C system (native iron, schreibersite, barringerite, murashkoite, and cohenite). The origin of phosphide-bearing associations is connected with the effect of highly reduced gases on earlier formed pyrometamorphic rocks.
Original language | English |
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Article number | 560 |
Pages (from-to) | 1-11 |
Number of pages | 11 |
Journal | Minerals |
Volume | 10 |
Issue number | 6 |
DOIs | |
State | Published - 1 Jun 2020 |
Keywords
- Barringerite
- Fluorkyuygenite
- H
- Hatrurim Complex
- Israel
- Mayenite
- Molecular hydrogen
- Negev Desert
- Pyrometamorphic rocks
- Raman spectroscopy
- Shreibersite
ASJC Scopus subject areas
- Geotechnical Engineering and Engineering Geology
- Geology